Sound generating devices for exhaust systems are utilized in the prior art, in order to reduce sound emissions of an exhaust system of a combustion engine or to artificially generate a desired engine sound. With respect to the sound generated by the exhaust gas stream, the sound generated by the sound generating device acts as counter-sound in the reduction of sound. The sound generating device for this purpose generates sound on one or more frequencies. This sound is phase-shifted with respect to the sound generated by the exhaust gas stream such that it attenuates the undesired sound emissions or at least eliminates the same at certain frequencies.
A sound generating device as mentioned above is known, for example, from DE 10 2012 201 725 A1. This document is concerned with the manufacture of an active muffler for an exhaust system at comparatively low cost.
In general, a sound generating device comprises a loudspeaker which divides the inner space of the housing into two sub-spaces. A first sub-space is located on that side of the loudspeaker to which the sound generated by the sound generating device is meant to propagate. A second sub-space is usually arranged on the opposite side of the loudspeaker. In this second sub-space, the excitation mechanism for the loudspeaker membrane, which generally comprises the associated electrical connection contacts, also is positioned. The two sub-spaces hence among other things are separated by the loudspeaker membrane.
Since the first sub-space is connected with the exhaust gas-carrying ducts of the exhaust system, the gas-tight sealing of the two sub-spaces serves to seal the second sub-space and thus the connection contacts and the electrical system of the loudspeaker towards the exhaust gas stream. This is necessary to protect the electrical contacts and lines on the rear side of the loudspeaker from corrosion by the chemically aggressive exhaust gases.
This sealing must be ensured over the entire service life of the sound generating device and thus the exhaust system. The attachment and the sealing of the loudspeaker in the housing are therefore of very great importance.
Thus, it is the object of the present invention to create a sound generating device for an exhaust system of a combustion engine of a vehicle, in which the sealing of the loudspeaker towards the housing is improved. In particular, a particularly long-lived sealing should be created. At the same time, there should be created a sound generating device which can be manufactured easily and at low cost.
In addition, a sufficient stiffness and a small overall height must be ensured.